Hi,

I have the a code with some parameters including

Nr= 0, 50, 100

Ha=0, 5, 10

EPSILONE= 0, 0.5, 1

Phiavg= 0.02, 0.06, 0.1

0.1<NBT<10

I can give the solution for higher values of 5<NBT<10 and there is no problem. However, As I reduce the values of NBT, the convergence of the problem is hard. for some values of parameters I cannot find the solution. for example:

Nr=Ha=0

EPSILONE=1

Phiavg=0.06

NBT=0.3

I would be most grateful if you can tel me how change the algorithm to find the solution in the range of all parameters.

Many thanks for your attentions in advance

The code has been attached

code_7-8-2014_(1).mw

Amir

Now that I got my units converted I have a new problem:

I have g/mol and g/cm^3, and the result is supposed to be per cm^3 too. So I would like to keep my grams as well as my  cm^3. However, Maple converts it all to kg and m^3!

That means I have to divide the final result by 10e6. No big deal, only that it looks strange on my worksheet (when I divide the units stay the same, so if I show that to someone they'll be amazed at the gigantic m^3 result number I got instead of just a few cm^3).

By the way, turing off the automatic unit cancellation (see link, my question a few days ago) does not change anything, the g->kg and cm^3->m^3 conversion take place as soon as I enter the values:

results in

and

gives

Hi guys,

im trying to solve the linear equation system:

Then, assigning the solutions:

Then, eliminating the RootOf's for variable a:

Unfortunately, a_explicit still contains RootOf's. How can I avoid this?

Thanks,

Martin

Hi all.

I want to know how do I declare symbol in maple. Say y=2x+b, I want maple to treat this y as a function of x with b as a constant (or symbol). How should I do that?

More specificaly, I am trying to ask maple to do some calculation for me. and it returns me "Fail". So I am suspecting that maple didn't take other letters as symbol. Here is my code:

with(Statistics); h := RandomVariable(Exponential(H)); simplify(PDF(h, t))

with(Statistics); g := RandomVariable(Exponential(G)); simplify(PDF(g, t))

constants := constants, Ps Pr

PDF(Ps*g*h/(Pr*g+2), t)

but maple return:

          Fail

Download Maple_Question_7.7.14.mw

Hi everyone,

I have a question regarding the simplification of an equation. Suppose I have and equation in maple such as (4*y^2 + 8*y + 8*sin(y))/(y^2 +1)=0. Is there a sequence of commands in Maple to simpliy this equation to (1/2)y^2 + y + sin(y)=0?

I know mulitplying the entire original equation by (1/8)*(y^2+1) would achieve the objective, but the equations I am generating are much longer and more complicated. The example above was chosen just to illustrate the goal.

Best,

Justin

Hello Maple-Primers!

I am trying to evaluate a system at many different points.  I would like to include an interpolation function in this system, but have thusfar been unsuccessful.

Usually, I solve a system symbolically by using eliminate and unapply:

eq[1] := A = M^3;
eq[2] := C = A*2;
eq[3] := D = N+3;
eq[4] := B = piecewise(A = 0, 0,C);
eq[5] := E = B*D;
elimsol:=eliminate(convert(eq,list),[A,B,C,D,E])[1];

unappsol:=unapply(elimsol,[N,M]);

unappsol(1,2);
{A = 8, B = 16, C = 16, D = 4, E = 64} <--- great!

Now, I want to include an interpolation function in the system of equations.  They look like this (see worksheet for actual interpolation function):

B_interp := (W,T) -> CurveFitting:-ArrayInterpolation([FC_Map_W,FC_Map_T],FC_Map,Array(1 .. 1, 1 .. 1, 1 .. 2, [[[W, T]]]),method=linear);

eq[5] := E = B_interp(N,M);

Error, (in CurveFitting:-ArrayInterpolation) invalid input: coordinates of xvalues must be of type numeric <-- bad!

Anyone have any ideas?  I've tried to use polynomials, but I can't seem to get a fit close enough for my purposes.

Maple_2D_Interpolate_FC.mw

A (probably) stupid question that is driving me crazy: how can I expand in Taylor series the following potential function

f(r_):=Int(Int(Int(G(r_-r0_)-(x_-r0_)*rho(r_))))?

essentially the Green representation formula for a harmonic function f in the whole 3d space.

Thanks in advance!

solve([x + 3*y + 5*z = 0,
7*x + 9*y + 11*z = 0,
13*x + 15*y + 17*z = 0],[x,y]);

Hi guys,

I'm trying to find the solutions to a nonlinear equation system:

mysol := solve({J*a = m*g*l*st-m*l*(c*cp*st+d*sp*st), cx*ux = cMx*xd+(Mx+m)*c+m*l*(-cp*pd^2*st-cp*st*td^2-2*ct*pd*sp*td+a*cp*ct-b*sp*st), cy*uy = cMy*yd+(My+m)*d+m*l*(2*cp*ct*pd*td-pd^2*sp*st-sp*st*td^2+a*ct*sp+b*cp*st), (-M*l^2*st^2+J)*b = m*l*sqrt(d^2-2*d*ct+ct^2+c^2*ct^2+(c^2*sp^2-2*c*cp*d*sp+cp^2*d^2)*st^2)}, {a, b, c, d})

The solution contains various implicit solutions with RootOf's. When trying to evaluate them by typing

allvalues(mysol);,

the returned set of solutions is about 800.000 characters long, but unfortunately contains various "+ [...15295 terms...] +" elements, and thus not displaying the full solution. The limits on the precision tab in the maple options are all disabled.
Does anybody know how to display the full expression, although it gets very long?

Thank you in advance,

Martin

Hi everyone,

I'm running Maple 18 and MapleSim 6.4 on my macbook pro 13 " with retina display and the GUI is blurred like there is no smoothing or the antialiasing is not working properly. I tried to find something helpfull in the setting but with no luck.

Is there something I can do to fix this?

Thanks

Carlo

Whenever I use the function changevar() and press ENTER, I always get the following output, despite paying

attention to the syntax

example:

g1:=changevar(q,g,t);

Output:

g1:=changevar(....)

Ideally, I would like the output to be the following:

g1:=...

What could be the problem with my code?

U

got an error when try to jacobian this

with(VectorCalculus):
f1 := -2*x1-x2; f2 := -x1-4*x2; g1 := 2*x1+3*x2-6; g2 := -x1; g3 := -x2;
penalty := lambda1*max(f1-M,0) + lambda2*max(f2-M,0) + (M^2)*(max(g1,0) + max(g2,0) + max(g3,0)):
obj := eval(penalty,[lambda1=3,lambda2=0.645,M=1]);
Hf := Jacobian(Jacobian(obj, [x1, x2, x3]), [x1, x2, x3]);

Error, invalid input: VectorCalculus:-Jacobian expects its 1st argument, f,
to be of type {Vector(algebraic), list(algebraic)}, but received 3*max(0, -2*x1-x2-1)+.645*max(0, -x1-4*x2-1)+max(0, 2*x1+3*x2-6)+max(0, -x1)+max(0, -x2)

Hello,

       How long can I expect Maple17 to take to algebraically solve a system of 14 nonlinear equations that has approximately 40% nonlinearity in its terms? I am running it on the machine right now, but have no idea what to expect. As mentioned before, I'm new to Maple...

Here is my code:

restart; eq1 := A*z-B*a*z-V*a*q-W*(b+d)*a = 0; eq2 := W*(b+d)*a-V*b*q-(F*G+B+D)*b*z = 0; eq3 := V*a*q-W*c*(b+d)-(B+C+E)*c*z = 0; eq4 := V*b*q+W*(b+d)*c-(B+C+D+F)*d*z = 0; eq5 := G*F*b*z-V*q*e-(B+H)*e*z = 0; eq6 := H*e*z-V*q*f-(B+S)*f*z = 0; eq7 := S*f*z-V*q*g-B*g*z = 0; eq8 := V*q*g+S*s*z-(B+C+E)*h*z = 0; eq9 := F*d*z+V*q*e-(B+C+H+T)*t*z = 0; eq10 := H*t*z+V*q*f-(U+B+C+2*S)*s*z = 0; eq11 := T*t*z-(B+H+Y)*u*z = 0; eq12 := U*s*z-(B+S)*v*z+H*u*z-Y*H*v*z/(H+S) = 0; eq13 := g-c-d-t-s-h = 0; eq14 := z-a-b-c-d-e-f-g-h-s-t-u-v = 0; soln := solve({eq1, eq10, eq11, eq12, eq13, eq14, eq2, eq3, eq4, eq5, eq6, eq7, eq8, eq9}, {a, b, c, d, e, f, g, h, q, s, t, u, v, z});

Thanks.

Greetings,

       I am new to Maple and this forum. I would like to obtain a Jacobian of a system of 12 ODEs. What have I done wrongly with my code?

eq_1 := -B*a+A-V*(c+d+t+s+h)*a/(a+b+c+d+e+f+g+h+s+t+u+v)-W*(b+d)*a/(a+b+c+d+e+f+g+h+s+t+u+v);
eq_2 := W*(b+d)*a/(a+b+c+d+e+f+g+h+s+t+u+v)-V*(c+d+t+s+h)*b/(a+b+c+d+e+f+g+h+s+t+u+v)-(F*G+B+D)*b;
eq_3 := V*(c+d+t+s+h)*a/(a+b+c+d+e+f+g+h+s+t+u+v)-W*(b+d)*c/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+E+C)*c;
eq_4 := V*(c+d+t+s+h)*b/(a+b+c+d+e+f+g+h+s+t+u+v)+W*(b+d)*c/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+C+D+F)*d;
eq_5 := G*F*b-V*(c+d+t+s+h)*e/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+H)*e;
eq_6 := H*e-V*(c+d+t+s+h)*f/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+S)*f;
eq_7 := S*f-V*(c+d+t+s+h)*g/(a+b+c+d+e+f+g+h+s+t+u+v)-B*g;
eq_8 := V*(c+d+t+s+h)*g/(a+b+c+d+e+f+g+h+s+t+u+v)+S*s-(B+E+C)*h;
eq_9 := F*d+V*(c+d+t+s+h)*e/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+C+H+T)*t;
eq_10 := H*t+V*(c+d+t+s+h)*f/(a+b+c+d+e+f+g+h+s+t+u+v)-(U+B+C+S+S)*s;
eq_11 := T*t+W*(b+d)*x/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+H+Y)*u;
eq_12 := U*s-(B+S)*v+H*u-Y*H*v/(H+S);
with(linalg);
J := Jacobian([eq_1, eq_2, eq_3, eq_4, eq_5, eq_6, eq_7, eq_8, eq_9, eq_10, eq_11, eq_12], [a, b, c, d, e, f, g, h, s, t, u, v]);

I am getting the message: 

 Vector(4, {(1) = ` 12 x 12 `*Matrix, (2) = `Data Type: `*anything, (3) = `Storage: `*rectangular, (4) = `Order: `*Fortran_order})

Thanks!!